﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Switch
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("请输入成绩：");


             int grade = Convert.ToInt32(Console.ReadLine());
            switch (grade / 10)
            { 
                case 10:

                case 9:

                     Console.WriteLine("优秀");
                     break;
                case 8:
                    Console.WriteLine("良好");
                    break;
                    case 7:
                    case 6:
                        Console.WriteLine("及格");
                        break;
                    default:
                        Console.WriteLine("不及格");
                        break;
             }

            Console.ReadKey();
        }
    }
}
